Conservatives estimates predict a nearly 50% increase in the current world population of approximately six billion people by the year 2050 (1998 United Nations. 1998 Revision of the official United Nations population estimates and projections. World population nearing 6 billion projected close to 9 billion by 2050, Population Division of the Department of Economics and Social Affairs. United Nations, New York, 998). This potential over-population, particularly in developing countries, is further complicated by the non-availability of proper easy-to-use, simple, cheap, least toxic and non-invasive method of contraception. Several contraceptive devices have been introduced till date and all of them suffer from certain constraints as enumerated below:
Though hormonal methods (oral contraceptives) are highly effective in preventing pregnancies, various complications and side effects on prolonged use can not be ruled out.
On the other hand, vasectomy and ligation of Fallopian tube never became popular because of their various complications, irreversibility and problems of recannulation.
The intrauterine devices (IUDs) also cause several complications, including uterine perforations, occasional bleeding etc.
The vaginal preparations are however relatively popular all over the world amongst the motivated couples, and because of their local and non-systemic application. However, these never give 100% contraceptive assurance.
The vaginal contraceptive compositions marketed in the USA primarily utilize nonionic detergents (surfactants) as their active ingredient. Of these, the most commonly used is nonoxynol-9 (N-9). Although N-9 is an extremely potent sperm immobilizing agent in vitro, but the marketed preparations are encountered with failures due to several reasons including the possibility of escape of first fraction of ejaculated sperms from its interaction with the active agents. In addition, N-9 can interfere with the natural vaginal environment and can cause irritation at a concentration that is recommended for use. N-9 and other spermicidal agents that have surfactant and cytotoxic properties have been proposed to prevent conception as a dispersing agent in spermicidal preparations (namely, Delfen, Gentersal and Ortho-Crème). However, relatively high failure rate of these surfactants in preventing pregnancies as well as evidence of adverse side effects have been documented (Stafford et al., 1998 Stafford, M K, Ward, H. Flanagan, A, Rosenstein, I J, Taylor-Robinson, D, Smith, J R, Weber, J and Kitchen, VS. Safety study of nonoxynol-9 as a vaginal microbicide: evidence of adverse effects. Journal of Acquired Immune Deficiency Syndromes, 17:327–331, 1998., Roddy et al., 1998—Roddy, R E, Zekeng, L, Ryan, K A, Tamoufe, U, Weir, S S and Wong, E L. A controlled trial of nonoxynol-9 film to reduce male-to-female transmission of sexually transmitted diseases—New England Journal of Medicine, 339: 504–510, 1998 and Homn. R E, Foldesy, R G and Hahn, D W. ORF 13904, a new long-acting vaginal contraceptive. Contraception, 32: 267–274, 1985).
For the last few decades, clove oil is being used in dental cream, mouthwash and various medicinal preparations at concentrations much higher than that cause sperm immobilization
For these reasons, it is imperative that a new type of highly active ingredient be identified and developed for vaginal contraceptive use, as it will be noninvasive and is expected to have least or no side effects.